LVM snapshot and Automatically Extend LVM Snapshots
Posted: 30 Mar 2024, 18:27
ORIGINAL ARTICLE(S):
1) Chapter 10. Snapshot of logical volumes
2) https://dustymabe.com/2012/03/04/automatically-extend-lvm-snapshots/
Creating LVM snapshots
1) Create a logical volume named origin from the volume group vg001:
2) Create a snapshot logical volume named snap of /dev/vg001/origin that is 100 MB in size:
3) Display the origin volume and the current percentage of the snapshot volume being used:
4) Optional: Extend the snapshot before its space becomes 100% full and becomes invalid by using any one of the following options:
snapshot_autoextend_threshold
Extends the snapshot after its usage exceeds the value set for this parameter. By default, it is set to 100, which disables automatic extension. The minimum value of this parameter is 50.
snapshot_autoextend_percent
Adds an additional space to the snapshot, which is the percent of its current size. By default, it is set to 20.
In the following example, after setting the following parameters, the created 1G snapshot extends to 1.2G when its usage exceeds 700M:
Example Automatically extend the snapshot
1) Chapter 10. Snapshot of logical volumes
2) https://dustymabe.com/2012/03/04/automatically-extend-lvm-snapshots/
Creating LVM snapshots
1) Create a logical volume named origin from the volume group vg001:
Code: Select all
lvcreate -L 1G -n origin vg001
Logical volume "origin" created.Code: Select all
lvcreate --size 100M --name snap --snapshot /dev/vg001/origin
Logical volume "snap" created.Code: Select all
lvs -a -o +devices
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert Devices
origin vg001 owi-a-s--- 1.00g /dev/sde1(0)
snap vg001 swi-a-s--- 100.00m origin 0.00 /dev/sde1(256)snapshot_autoextend_threshold
Extends the snapshot after its usage exceeds the value set for this parameter. By default, it is set to 100, which disables automatic extension. The minimum value of this parameter is 50.
snapshot_autoextend_percent
Adds an additional space to the snapshot, which is the percent of its current size. By default, it is set to 20.
In the following example, after setting the following parameters, the created 1G snapshot extends to 1.2G when its usage exceeds 700M:
Example Automatically extend the snapshot
Code: Select all
vi /etc/lvm.conf
snapshot_autoextend_threshold = 70
snapshot_autoextend_percent = 20